Heroes Return - Once an Avenger! [The Morgan Conquest]: Part 1 of 3 - "And there came a Day...!" Story by Kurt Busiek. Art by George Perez and Al Vey. One year ago the greatest heroes in the Marvel Universe, the Avengers and Fantastic Four, fought the mutant menace known as Onslaught and were sucked into an alternate universe. Earth's Mightiest Heroes have returned from the pocket universe of the Heroes Reborn just in time for an adventure so epic that it will take the greatest assemblage of Avengers ever put together. Every hero who has ever been a member of the team must unite to face a force so dangerous that it threatens the very fabric of reality.